[libsigcplusplus] Update method names in comments

[Kjell Ahlstedt <kjellahl src gnome org>]

commit dd351b9f4b83035fd8f916a87f91ab7a18ff9b78
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Mon Jul 17 15:41:10 2017 +0200

    Update method names in comments
    
    Some method names have changed from libsigc++2 to libsigc++3, but not all
    comments have been changed accordingly.
    
    * sigc++/connection.h: Correct some parameter names in doxygen comments.
    connection::notify() has been replaced by a private method in weak_raw_ptr.
    * sigc++/signal_base.[cc|h]: signal_impl::notify() has been renamed
    notify_self_and_iter_of_invalidated_slot().

 sigc++/connection.h   |    8 ++++----
 sigc++/signal_base.cc |   10 ++++++----
 sigc++/signal_base.h  |   10 +++++-----
 3 files changed, 15 insertions(+), 13 deletions(-)
---
diff --git a/sigc++/connection.h b/sigc++/connection.h
index 7847810..4b4926e 100644
--- a/sigc++/connection.h
+++ b/sigc++/connection.h
@@ -43,12 +43,12 @@ struct SIGC_API connection
   connection(const connection& c);
 
   /** Constructs a connection object from a slot object.
-   * @param sl The slot to operate on.
+   * @param slot The slot to operate on.
    */
   explicit connection(slot_base& slot);
 
   /** Overrides this connection object copying another one.
-   * @param c The connection object to make a copy from.
+   * @param src The connection object to make a copy from.
    */
   connection& operator=(const connection& src);
 
@@ -92,8 +92,8 @@ struct SIGC_API connection
 private:
   void set_slot(const sigc::internal::weak_raw_ptr<slot_base>& sl);
 
-  /* Referred slot. Set to zero from notify().
-   * A value of zero indicates an "empty" connection.
+  /* Referred slot. Set to nullptr when the referred slot is deleted.
+   * A value of nullptr indicates an "empty" connection.
    */
   sigc::internal::weak_raw_ptr<slot_base> slot_;
 };
diff --git a/sigc++/signal_base.cc b/sigc++/signal_base.cc
index 5218f20..67f493e 100644
--- a/sigc++/signal_base.cc
+++ b/sigc++/signal_base.cc
@@ -24,7 +24,8 @@ namespace internal
 {
 
 // Data sent from signal_impl::insert() to slot_rep::set_parent() when a slot is
-// connected, and then sent from slot_rep::disconnect() to signal_impl::notify()
+// connected, and then sent from slot_rep::disconnect() to
+// signal_impl::notify_self_and_iter_of_invalidated_slot()
 // when the slot is disconnected. Bug 167714.
 struct self_and_iter : public notifiable
 {
@@ -63,8 +64,8 @@ signal_impl::operator delete(void* p)
 void
 signal_impl::clear()
 {
-  // Don't let signal_impl::notify() erase the slots. It would invalidate the
-  // iterator in the following loop.
+  // Don't let signal_impl::notify_self_and_iter_of_invalidated_slot() erase the slots.
+  // It would invalidate the iterator in the following loop.
   // Don't call shared_from_this() here. clear() is called from the destructor.
   // When the destructor is executing, shared_ptr's use_count has reached 0,
   // and it's no longer possible to get a shared_ptr to this.
@@ -73,7 +74,8 @@ signal_impl::clear()
   signal_impl_exec_holder exec(this);
 
   // Disconnect all connected slots before they are deleted.
-  // signal_impl::notify() will be called and delete the self_and_iter structs.
+  // signal_impl::notify_self_and_iter_of_invalidated_slot() will be called and
+  // delete the self_and_iter structs.
   for (auto& slot : slots_)
     slot.disconnect();
 
diff --git a/sigc++/signal_base.h b/sigc++/signal_base.h
index 9b1e815..514ddfe 100644
--- a/sigc++/signal_base.h
+++ b/sigc++/signal_base.h
@@ -36,11 +36,11 @@ namespace internal
 {
 
 /** Implementation of the signal interface.
- * signal_impl manages a list of slots. When a slot becomes
- * invalid (because some referred object dies), notify() is executed.
- * notify() either calls slots_.erase() directly or defers the execution of
- * erase() to sweep() when the signal is being emitted. sweep() removes all
- * invalid slots from the list.
+ * signal_impl manages a list of slots. When a slot becomes invalid (because some
+ * referred object dies), notify_self_and_iter_of_invalidated_slot() is executed.
+ * notify_self_and_iter_of_invalidated_slot() either calls slots_.erase() directly
+ * or defers the execution of erase() to sweep() when the signal is being emitted.
+ * sweep() removes all invalid slots from the list.
  */
 struct SIGC_API signal_impl
  : public std::enable_shared_from_this<signal_impl>